Home connect speed very bad

I stuggle with the speed I apply for 200mbps but it's only 18mbps. Why do I have pay for this speed if I dont received it. Eveyday I have to call them most of the people are very helpfull. The router was working so I can connet to the internet. Now I call again and Princess help me she login at anydesk and change the settings, I can't connect she said becausr all our phones and pc's are not compactable for the router. But before she change it, the phones and pc"s was compactable.